之前一直在纠结Xen-tools的作用，今天偶然在官方资料上瞄到了：  

   XenServer Tools must be installed for each Virtual Machine (Windows and Linux) in order for the VM to have a fully supported configuration, and to be able to use the XenServer management tools (the xe CLI or XenCenter).

   A Windows VM will function without them, but performance will be significantly hampered unless the tools are installed./不安装也能运行，但是性能在很大程度上会被限制


Without the tools being installed, you cannot:

• Cleanly shut down a VM /干净利落的关闭一台虚拟机

• Cleanly reboot a VM /干净利落的重启一台虚拟机

• Suspend a VM /挂起一台虚拟机

• Migrate a running VM (XenMotion) /利用XenMotion迁移一台正在运行的虚拟机

• Use the checkpoint and roll back feature /使用快照和从快照恢复功能

• Dynamically adjust the number of vCPUs assigned to a running Linux VM- Windows VMs require a reboot for this to take effect /动态调整vCPU数量，需要重启才能生效


For further information about XenServer Tools see the section called “XenServer Tools”


Warning:

Running a VM without installing the XenServer Tools is not a supported configuration.

/运行一台不安装Xen-tools的虚拟机是不建议的配置